Key structure convertible between digital and analog switch modes and switching method thereof

ABSTRACT

A key structure including a circuit board, a membrane, a positioning frame, a sensor module, a scissor leg, and a key cap is provided. The membrane is disposed on the circuit board and is electrically connected to each other. The positioning frame is disposed on the membrane. The sensor module is disposed on the membrane and is electrically connected to the circuit board. The scissor leg is connected to the positioning frame and is adapted to move up and down relative to the positioning frame. The key cap is detachably disposed at the scissor leg and is spaced with positioning frame. The key cap has a reflective plane and a shaft component. The reflective plane faces the membrane. The shaft component is extended from the reflective plane and penetrates through the scissor leg and the positioning frame to abut the membrane. The sensor module is aligned with the reflective plane.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 107143627, filed on Dec. 5, 2018. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND Technical Field

The disclosure relates to a key of a notebook computer, and inparticular to a key structure of a switchable digital control signal andan analog control signal and a mode switching method thereof.

Description of Related Art

A notebook computer applied to electronic sports nowadays allows aplayer to play games mainly through controlling input devices such as amouse and a keyboard. Compared to a desktop computer, the notebookcomputer is lighter and more portable, allowing the player to startgames with an external mouse; wherein the keyboard of the notebookcomputer is built-in, and each key input a digital signal through afinger press of the user, triggering the two signals of ON and OFFrespectively when the keys are pressed and are not pressed.

However, existing keys nowadays are mostly digital keys and can onlyinput the ON/OFF signal without implementing a continuous functionsignal of an analog key. Briefly, the analog key may sense the level ofthe user's press strength in a certain deformation range and transformthe strength into a corresponding numerical value in the game to makethe control of the game more closed to reality.

For instance, in a car-racing game, when the user controls a racing carthrough digital keys, the throttle of the racing car only has to statesof “full-open” (ON signal) and “full-closed” (OFF signal). As acomparison, when the user controls the throttle of the racing car withanalog keys, the game program may transform the press into acorresponding throttle response according to the level of the depth ofthe press to the analog key.

Thus, to experience the gameplay of an analog control, the existingusers need to install an extra analog joystick or an analog key.However, the extra installation contradicts the effects and purposes oflightness and portability of the notebook computer. Also, theinstallation may not be compatible with the mouse easily.

SUMMARY

The disclosure provides a key structure and a mode switch methodthereof, allowing the key structure to switch between an analog mode anda digital mode freely, and thus possesses broad practicability.

The key structure of the disclosure includes a circuit board, amembrane, a positioning frame, a sensor module, a scissor leg and a keycap. The membrane is disposed on the circuit board and is electricallyconnected to each other. The positioning frame is disposed on themembrane. The sensor module is disposed on the membrane and iselectrically connected to the circuit board. The scissor leg isconnected to the positioning frame and is adapted to move up and downrelative to the positioning frame. The key cap is detachably disposed atthe scissor leg and is spaced with the positioning frame. The key caphas a reflective plane and a shaft component. The reflective plane facesthe membrane. The shaft component is extended from the reflective planeand penetrates through the scissor leg and the positioning frame to abutthe membrane. The sensor module is aligned with the reflective plane;wherein the sensor module is adapted to detect a press stroke of the keycap relative to the membrane; when the key cap is pressed, a digitalcontrol signal or an analog control signal is triggered through themembrane or the sensor module.

The mode switching method of the disclosure includes a key structureincluding a circuit board, a membrane, a position frame, a sensormodule, a scissor leg and a key cap. The membrane is disposed on thecircuit board and is electrically connected to each other. Thepositioning frame is disposed on the membrane. The sensor module isdisposed on the membrane and is electrically connected to the circuitboard. The scissor leg is connected to the positioning frame and isadapted to move up and down relative to the positioning frame. A key caphaving a elastic component is disposed at the scissor leg, making theelastic component abut the membrane to switch on the digital mode. Whenthe key cap is pressed, the elastic component generates a non-lineardeformation to squeeze the membrane to further trigger a digital controlsignal. The key cap having the elastic component is replaced by anotherkey cap having an elastic component to make the elastic component abutthe membrane to switch on the analog mode. When the key cap is pressed,the elastic component generates a linear deformation to further triggeran analog control signal through a press stoke of the key cap relativeto the membrane detected by the sensor module.

Based on the above, the key structure of the disclosure may freelyreplace the key cap having different shaft components. When the userpresses the key cap, the corresponding digital control signal or analogcontrol signal may be triggered through the membrane or the sensormodule. Therefore, the key structure may be switched to the digital mode(suitable for word processing and web page browsing) and to the analogmode (suitable for electronic sports and game controlling) according tothe user's requirement. Thus, compared to the keyboard of the notebookcomputer, the key structure of the disclosure has broad practicability.

Further, the key structure of the disclosure may achieve the function ofswitching between the digital and analog modes through only replacingthe key cap; compared to the method of using an existing external analogjoystick, the key structure has advantages of detachability and easyportability; also, the scenario of the incompatibility between theanalog joystick and the mouse may be avoided.

In order to make the features and advantages of the disclosure mentionedabove more understandable, embodiments will be described in detail belowwith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a key structure according toan embodiment of the disclosure.

FIG. 2A is a perspective see-through schematic view of a key cap havinga elastic component and installed on the key structure of FIG. 1.

FIG. 2B is a perspective schematic view of the key cap having a elasticcomponent of FIG. 2A.

FIG. 2C and FIG. 2D are sectional schematic views of a press action ofthe key structure of FIG. 2A.

FIG. 3A is a perspective see-through schematic view of the key caphaving an elastic component and installed on the key structure of FIG.1.

FIG. 3B is a perspective schematic view of the key cap having an elasticcomponent of FIG. 3A.

FIG. 3C and FIG. 3D is a sectional schematic view of the press action ofthe key structure of FIG. 3A.

FIG. 4 is a block flow diagram of the key structure switching to adigital mode and an analog mode according to the disclosure.

FIG. 5A is an exploded perspective view of parts of components of thekey structure according to another embodiment of the disclosure.

FIG. 5B is a sectional schematic view of a key structure of FIG. 5A.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is an exploded perspective view of a key structure according toan embodiment of the disclosure. FIG. 2A is a perspective see-throughschematic view of a key cap having an elastic component and installed onthe key structure of FIG. 1. FIG. 3A is a perspective see-throughschematic view of the key cap having an elastic component and installedon the key structure of FIG. 1.

Please refer to FIG. 1. A key structure 100 of the disclosure applies toa built-in keyboard of a notebook computer. In another embodiment, thekey structure of the disclosure may be applied to an external keyboardof a desktop computer. Generally, an existing keyboard has a pluralityof key structures, and each key structure respectively represent todifferent orders. When each key structure is not pressed, the judgementof a keyboard system is OFF, and the order is not triggered. When eachpress structure is pressed, the judgement of the keyboard system is ON,and a corresponding order is triggered to achieve actions such asinputting characters, controlling games or executing programs. Briefly,existing keyboards are mostly the digital modes judging ON/OFF signals.

Please refer to FIG. 1, FIG. 2A and FIG. 3A. The key structure 100 ofthe disclosure includes a circuit board 110, a membrane 120, apositioning frame 130, a sensor module 140, a scissor leg 150 and a keycap 160.

The circuit board 110 is used to form a required conductor pattern andis installed on each kind of electronic component to perform digitallogic judgement. The external circuit board 110 is adapted to beelectrically connected to a control core of a computer, and may transmitthe judged signals and orders to the control core of the computer. Inthe present embodiment, the circuit board 110, for example, adopts aprinted circuit board or a flexible printed circuit board (FPC), whichis determined by the requirement of the manufacturing process; and thedisclosure is not limited hereto.

The membrane 120 is disposed on the circuit board 110 and the circuitboard 110 is electrically connected to each other. The membrane 120 hasa plurality of trigger buttons 121. When each trigger button 121 ispressed and deformed, an electrical signal is triggered and theelectrical signal is transformed to a corresponding order after thelogic judgment through the circuit board 110.

The positioning frame 130 is disposed on the membrane 120. In thepresent embodiment, the positioning frame adopts, for example, metal,plastic, or other materials that may integrally formed.

The sensor module 140 is disposed on the membrane 120 and iselectrically connected to the circuit board 110. The sensor module 140detects sensor components of long and short distances through, forexample, light source, ultrasonic, or other similar means and acontinuous change of long and short distances transforms into acorresponding electrical signal.

The scissor leg 150 is connected to the positioning frame 130 and isadapted to move up and down relative to the positioning frame 130. Thekey cap 160 may be detachably disposed at the scissor leg and is spacedwith the position frame 130, which explains that the key cap 160 maymove up and down vertically along with the scissor leg 150.

Further, the key cap 160 has a reflective plane RS and a shaft component161. The reflective plane RS is disposed to the bottom of the key cap160 and faces the membrane 120. The shaft component 161 is extendeddownward from the reflective plane RS and penetrates through the scissorleg 150 and the positioning frame 130 to abut the membrane. Moreover,the sensor module 140 is aligned with the reflective plane RS and is notblocked by the positioning frame 130 and the scissor leg 150, so as toavoid affecting the judgement of the sensor module 140 toward thedistances. Besides, the reflective plane RS is, for example, opaque andis favorable for reflecting light.

FIG. 2B is a perspective schematic view of the key cap having an elasticcomponent of FIG. 2A. FIG. 2C and FIG. 2D are sectional schematic viewsof a press action of the key structure of FIG. 2A. FIG. 3B is aperspective schematic view of the key cap having elastic component ofFIG. 3A. FIG. 3C and FIG. 3D is a sectional schematic view of the pressaction of the key structure of FIG. 3A.

Wherein the sensor module 140 is adapted to detect a press stroke H1 ofthe key cap 160 relative to the membrane 120. When pressing the key cap160 towards the membrane 120, the shaft component 161 of the key cap 160is adapted to squeeze the trigger button 121 of the membrane 120 andgenerates a deformation to further trigger the digital control signal;or, when pressing the key cap 160 towards the membrane 120, the sensormodule 140 triggers the corresponding analog control signal bytransforming the continuous change of the press stroke H1 of the key cap160.

Please refer to FIGS. 1, 2A and 2B. The positioning frame 130 has aplurality of hook portions, and the key cap 160 has a plurality of clampportions 162. The plurality of hook portions hook up one end of thescissor leg 150 away from the key cap 160; and the a plurality of clampportions 162 clamp the other end of the scissor leg 150 away from thepositioning frame 130, making the scissor leg 150 limited by thepositioning frame 130 and the key cap 160 to have a certain range of upand down movement.

Further, the positioning frame 130 has a plurality of holes THcorresponding to the reflective plane RS of the key cap 160 and containsparts of the shaft components 161 and the sensor module 140.

Please refer to FIGS. 1, 3A and 3C. The sensor module 140 includes alight emitting device 141 and a light detector 142.

The light emitting device 141 is, for example, a light emitting diode(LED), and is adapted to transmit a light source L to the reflectiveplane RS of the key cap 160; and parts of the light source L istransmitted to the light detector 142 after the reflection of thereflective plane RS. The light detector 142 is adapted to receive anddetect the light intensity after the reflection of the light source L.The change of the light intensity is used to judge the size of the pressstroke of the key cap 160; and the change of the light intensity istransformed into a corresponding analog control signal.

Please refer to FIG. 2A to FIG. 2D. The shaft component 161 of the keycap 160 includes a elastic component R abutting the membrane 120 and thereflective plane RS respectively, and is adjacent to the sensor module140. When the key cap 160 is pressed towards the membrane 120, theelastic component R is driven to generate a non-linear deformation;wherein an initial value of a press stroke H1 of the key cap 160relative to the membrane 120 is 2.2 mm, which is a scenario that the keycap 160 is not pressed by external force.

Please refer to FIG. 3A to FIG. 3D. The shaft component 161 of anotherkey cap 160 includes an elastic component S respectively abutting themembrane 120 and the reflective plane RS and being adjacent to thesensor module 140. When the key cap 160 is pressed towards the membrane120, the elastic component S is driven to generate a linear deformation.An initial value of a press stroke H2 of the key cap 160 relative to themembrane 120 is 2.8 mm, which is a scenario that the key cap 160 is notpressed by an external force.

For example, the weaker the spectral intensity received by the lightdetector 142 is, the larger the press stroke H2 of the key cap 160 is,which explains that the key cap 160 is relatively away from the membrane120; on the contrary, the stronger the spectral intensity received bythe light detector 142 is, the smaller the press stroke H2 of the keycap 160 is, which explains that the key cap 160 is relatively closed tothe membrane 120. Therefore, with the difference of the press stroke H2,the control of the press in different level is implemented.

Please refer to FIG. 2B and FIG. 3B. The key cap 160 has a plurality offixed portions 163 disposed on a central position of the reflectiveplane RS; and the shaft component 161 and the fixed portion 163 areengaged with each other. Further, one end portion of the elasticcomponent R is disposed among the plurality of fixed portions to contactthe inner wall surface IS of the plurality of fixed portions 163 toimplement the engaging relation. One end portion of the elasticcomponent S surrounds the periphery of the plurality of fixed portions163, and a gap of the elastic component S contains the bumps of theplurality of fixed portions 163 to implement the engaging relations.

FIG. 4 is a block flow diagram of the key structure switching to adigital mode and an analog mode according to the disclosure.

Please refer to FIG. 1, FIGS. 2B and 2C and FIG. 4. When the userchooses to switch to the digital mode, a key cap 160 having the elasticcomponent R is put on. The key cap 160 having the elastic component R isdisposed at the scissor leg, making the elastic component R abut themembrane 120. After the key cap having the elastic component R isdisposed, the sensor module 140 simultaneously detects the press strokeH1 (2.2 mm as mentioned above) of the key cap 160 relative to themembrane 120, and switch off the sensor module 140 through a switch.

When the user presses the key cap 160 downward, the elastic component Ris driven to generate the non-linear deformation to squeeze the triggerbutton 121 of the membrane 120 to further trigger the digital controlsignal (which is ON signal). When the user on longer presses the key cap160, the elasticity of the elastic component R is restored and thetrigger button 121 of membrane 120 is released to further trigger thedigital control signal (which is OFF signal).

Please refer to FIG. 1, FIGS. 3B and 3C and FIG. 4. When the userchooses to switch to the analog mode, the key cap 160 having the elasticcomponent R is replaced by another key cap 160 having elastic componentS, making the elastic component S abut the membrane 120. After the keycap 160 having the elastic component S is disposed, the sensor module140 simultaneously detects the press stroke of the press stroke H2 (2.8mm as mentioned above) of the key cap 160 relative to the membrane 120,and turns on the sensor module 140 through a switch.

When the user presses the key cap 160 downward, the elastic component Sgenerates a linear deformation. The key cap 160 is relatively closed tothe membrane 120, and further trigger a continuous analog control signalthrough the sensor module 140 detecting the change of the press strokeH2 (gradually smaller) of the key cap 160 relative to the membrane 120.When the user no longer press the key cap 160, the elasticity of theelastic component R is restored to make the key cap 160 gradually awayfrom the membrane 120; meanwhile, the press stroke H2 also generateschanges (gradually stronger) to trigger a continuous analog controlsignal.

The light detector 142 of the sensor module 140 is adapted to thereceive and detect the light intensity after the light reflection tocalculate the change of the press stroke H2 of the key cap, and make thelight intensity transform into a corresponding analog control signal,therefore the control of difference in game may be virtually closed toreality, like the level of controlling the accelerator and brake inracing games, or the height of jump and the speed of moving of acharacter.

In addition, the key structure 100 of the disclosure may simulate thedigital mode under the analog mode. The sensor module 140 set a middlevalue (1.4 mm for example) in advance. When the press stroke H2 of thekey cap 160 relative to the membrane 120 is greater than the middlevalue of the sensor module 140, the OFF signal is triggered. When thepress stroke H2 of the key cap 160 relative to the membrane 120 issmaller than the middle value of the sensor module 140, the ON signal istriggered. Therefore, the user may output the digital control signalunder the analog mode without replacing the key cap repeatedly.

FIG. 5A is an exploded perspective view of parts of components of thekey structure according to another embodiment of the disclosure. FIG. 5Bis a sectional schematic view of a key structure of FIG. 5A.

Please refer to FIG. 5A and FIG. 5B. The differences between the keystructure 100A of the present embodiment and the key structure 100 ofFIG. 2A are that the scissor leg 150 a of the key structure 100Aincludes an installation panel 151 a. The installation panel 151 acovers on the sensor module 140 a. To describe in detail, the lightemitting device 141 a of the sensor module 140 a is adapted to transmita light source L to the bottom surface BS of the installation panel 151a, and parts of the light source L is transmitted to the light detector142 a after being reflected by the bottom surface BS. Further, the keycap 160 a may be detachably disposed on the top surface TS of theinstallation panel 151 a for easy replacements of the key caps of otherstyles.

Summing up, the key structure of the disclosure may freely replace thekey cap having different shaft components. When the user presses the keycap, the corresponding digital control signal or the analog controlsignal may be triggered through the membrane or the sensor module.Therefore, the key structure may be switched to the digital mode(suitable for word processing and web page browsing) and to the analogmode (suitable for electronic sports and game controlling) according tothe user's requirement. Thus, compared to the keyboard of the existingnotebook computer, the key structure of the disclosure has broadpracticability.

Further, the key structure of the disclosure may achieve the function ofswitching between the digital and analog modes through only replacingthe key cap; compared to the method of using an existing external analogjoystick, the key structure has advantages of detachability and easyportability; also, the scenario of the incompatibility between theanalog joystick and the mouse may be avoided.

Although the disclosure has been disclosed in the above embodiments, theembodiments are not intended to limit the disclosure, and those skilledin the art may make some modifications and refinements without departingfrom the spirit and scope of the disclosure. Therefore, the scope of thedisclosure is defined by the claims attached below.

What is claimed is:
 1. A key structure comprising: a circuit board; amembrane disposed on the circuit board and electrically connected to thecircuit board; a positioning frame disposed on the membrane; a sensormodule disposed on the membrane and electrically connected to thecircuit board; a scissor leg connected to the positioning frame andadapted to move up and down relative to the positioning frame; a key capdetachably disposed at the scissor leg and spaced with the positioningframe, and the key cap has a reflective plane facing the membrane, andthe sensor module is aligned with the reflective plane; and a shaftcomponent, extending from the reflective plane and penetrating throughthe scissor leg and the positioning frame to abut the membrane, whereinthe sensor module is adapted to detect a press stroke of the key caprelative to the membrane, and when the key cap is pressed, a digitalcontrol signal or an analog control signal is triggered through themembrane or the sensor module, wherein the sensor module comprises alight emitting device and a light detector, and the light emittingdevice is adapted to transmit a light source to the reflective plane,and the light source is transmitted to the light detector after thereflection, and the light detector is adapted to receive and detect thelight intensity after the reflection of the light source.
 2. The keystructure according to claim 1, wherein the shaft component is adaptedto squeeze the membrane and to generate a deformation.
 3. The keystructure according to claim 1, wherein the positioning frame has aplurality of hook portions, and the key cap has a plurality of clampportions, and the plurality of hook portions hook up one end of thescissor leg which is away from the key cap, and the plurality of clampportions clamp the other end of the scissor leg which is away from thepositioning frame.
 4. The key structure according to claim 1, whereinthe key cap has a plurality of fixed portions disposed on a centralposition of the reflective plane, and the shaft component and theplurality of fixed portions are engaged with each other.
 5. The keystructure according to claim 1, wherein the positioning frame has aplurality of holes corresponding to the reflective plane of the key capand containing the shaft component and the sensor module.
 6. The keystructure according to claim 1, wherein the scissor leg comprises aninstallation panel covering the sensor module, and the key cap isdetachably disposed on the installation panel.
 7. The key structureaccording to claim 1, wherein the shaft component comprises a elasticcomponent abutting the membrane and the reflective plane respectivelyand being adjacent to the sensor module, and when the key cap is pressedtowards the positioning frame, the elastic component is driven agenerate non-linear deformation.
 8. The key structure according to claim7, wherein an initial value of a press stroke of the key cap relative tothe membrane is 2.2 mm.
 9. The key structure according to claim 1,wherein the shaft component comprises an elastic component abutting themembrane and the reflective plane respectively and being adjacent to thesensor module, and when the key cap is pressed towards the positioningframe, the elastic component is driven to generate a linear deformation.10. The key structure according to claim 9, wherein an initial value ofa press stroke of the key cap relative to the membrane is 2.8 mm.
 11. Amode switching method comprising: a key structure comprising: a circuitboard; a membrane disposed on the circuit board and electricallyconnected to the circuit board; a positioning frame disposed on themembrane; a sensor module disposed on the membrane and electricallyconnected to the circuit board; and a scissor leg connected to thepositioning frame and adapted to the move up and down relative to thepositioning frame; disposing a first key cap having an elastic componentat the scissor leg, making the elastic component abut the membrane toprepare for a digital mode; when pressing the first key cap, the elasticcomponent generates a non-linear deformation to squeeze the membrane tofurther trigger a digital control signal; replacing the first key caphaving the elastic component with a second key cap having an elasticcomponent, making the elastic component abut the membrane to prepare foran analog mode, wherein the second key cap has a reflective plane facingthe membrane, and the sensor module is aligned with the reflectiveplane; and when pressing the second key cap, the elastic component ofthe second key cap generates a linear deformation to trigger an analogcontrol signal through the sensor module detecting the change of a pressstroke of the second key cap relative to the membrane.
 12. The modeswitching method according to claim 11, wherein the sensor modulecomprises a light emitting device and a light detector, and the lightemitting device is adapted to transmit a light source to the reflectiveplane and the light source is transmitted to the light detector afterthe reflection, and the light detector is adapted to receive and detectthe light intensity of the light source after the reflection tocalculate the press stroke of the second key cap and to transform thelight intensity into the corresponding analog control signal.
 13. Themode switching method according to claim 11, wherein while in the analogmode, the sensor module sets a middle value, and when the press strokeof the second key cap relative to the membrane is greater than themiddle value, an OFF signal is triggered, and when the press stroke ofthe second key cap relative to the membrane is smaller than the middlevalue, an ON signal is triggered.
 14. The mode switching methodaccording to claim 11, further comprising turning off the sensor moduleafter disposing the first key cap having the elastic component at thescissor leg.
 15. The mode switching method according to claim 11,wherein turning on the sensor module after replacing the first key capwith the second key cap.